New Features:
- Connection objects have a new peer_address attribute, which is
equivilent to calling ``getpeername()`` on sockets.
Bugs Fixed:
- Servers using unix-domain sockets didn't clean up socket files.
- When testing listeners were closed, handle_close, rather than close,
was called on server connections.

Bug Fixed:
- When using zc.ngi.testing and a server sent input and closed a
connection before set_handler was called on the client, the input
sent by the server was lost.
- By default, calling close on a connection could caause already
written data not to be sent. Now, don't close connections until
data passed to write or writelines as, at least, been passed to the
underlying IO system (e.g. socket.send).
(This means the undocumented practive of sending zc.ngi.END_OF_DATA
to write is now deprecated.)

Refactored ``zc.ngi.async`` thread management to make the blocking
APIs unnecessary. ``zc.ngi.async.blocking`` is now deprecated.
Made it possible to declare interfaces without zope.interface being
present and added interface declarations on the implementations.
Moved ConnectionFailed to tghe interfaces module.

Added support for running multiple ``async`` implementations in
separate threads. This is useful in applications with fewer network
connections and with handlers that tend to perform long-lating
computations that would be unacceptable with a single select loop.

New Features:
- New improved documentation
- Support for writing request handlers in an imperative style using
generators.
- Cleaner testing interfaces
- Added a new blocking client request interface,
``zc.ngi.blocking.request``. Other older blocking APIs are
deprecated.
- Dropped support for Python 2.4.
Bugs Fixed:
- The ``Sized`` request adapter's ``writelines`` method was broken.
- There we a number of problems with error handling in the ``async``
implementation.

New Features:
- New improved documentation
- Support for writing request handlers in an imperative style using
generators.
- Cleaner testing interfaces
- Added a new blocking client request interface,
``zc.ngi.blocking.request``. Other older blocking APIs are
deprecated.
- Dropped support for Python 2.4.
Bugs Fixed:
- The ``Sized`` request adapter's ``writelines`` method was broken.
- There we a number of problems with error handling in the ``async``
implementation.